package PATBrushQuestions;

import java.util.Scanner;
import java.util.Stack;

public class Test {

}

class Solution {
    public static void main(String[] args) {
        long a = new Scanner(System.in).nextLong();
        long sum = 0;
        long b = a;
        do {
            sum += b % 10;
            b = (b / 10);
        } while (b != 0);
        switch ((int) sum) {
            case 10:
                System.out.println("ten");
        }
        System.out.println(sum);
    }
}





